Category Archives: News

Morning of 13th November: Continuing our shells collection cruise, our next site, a little further south on the Faroes Bank, came up with another surprise: hundreds of live collected specimens of Glycymeris glycymeris. We know this species (which can live up to 200 years) from St Kilda, the west coats of Scotland and points south, but we weren’t expecting to find it this far west in the north Atlantic and as far as I know it has not been found elsewhere in the Faroes.

Shortly afterwards, the weather began to turn, and in the light of predicted bad weather around the Faroes, we decided to head across to our other main area of interest, where we were planning to collect shells for Tamara. This was Viking Bank in the northern North Sea/Norwegian Sea. Tamara and Rob planned a full 80 potential stations in three separate areas. Winds reached force 8 on the journey across to Viking Bank, and we were thankful for the relative stability of GO Sars. At a session of presentations in the ship’s seminar room, we got a bit of detail about the very promising progress with the ARAMACC projects.

However, when we resumed dredging earlier this morning, the first tow on Viking Bank turned up nothing except a few chunks of mud.

Evening of 14th November: We’ve worked on two main sites on Viking Bank with variable success. Modern Arctica islandica here are small compared with specimens from earlier in the Holocene. This may reflect sea level rise in the area: early Holocene specimens, living when large parts of the North Sea were still dry land, would have been living in coastal environments, with more nutrients, and were therefore able to grow faster than is possible nowadays. These older shells have the kind of size and thickness that we see nowadays in Arctica from around the UK coast.

While some trawls turned up the older shells in large numbers, more recent specimens, and especially the live animals that Tamara was most interested in seemed to be more elusive. A small adjustment to the connection between the winch and the dredge may have had the effect of allowing the dredge to dig deeper into the sediment, and the final trawl of the afternoon shift produced about 30 live clams.

GO Sars waits in Bergen before beginning the ARAMACC cruise to the Faroes. Picture: Paul Butler

We left Bergen at 17:00 Saturday 8th Nov, and took a 36 hour transit to first station (the seas reasonably calm considering the time of year), arriving at our first collection site off the SE of the Faroes at about 5am Monday 10th Nov.

10th November: With sauna, solarium and gym, GO Sars is a well equipped ship. I’m not sure how much time we’ll have to use them though, since all the scientists will spend 12 hours of each day collecting and processing shells (and some are having to spend time in their rooms “acclimatizing” to life at sea). For the past 24 hours we have been working off the SE side of the Faroes, at a grid of sites where Arctica has been collected before. Here, we’ve collected a fair number of dead shells and a few live specimens, and also some shells from animals that died more recently (articulated shells* – these are cases where the two valves are still attached even though there is no animal inside them). Most of the dead shells are of uncertain date; experience of other sites suggests that they could have lived anything from a few hundred to a few thousand years ago. They are generally in good condition, however, and may easily contribute to a long chronology.

Rob Witbaard (left) and Juan Estrella shovel a pile of shells – mostly dead Arctica valves – that have just been dredged from a site off the SW Faroes. Picture: Nina Whitney

Morning of 11th November: Switching the following night to a site off the SW of the islands, we struck dead Arctica gold. The four dredges we hauled (for six minutes each) were brimful with shell material, nearly all of it single Arctica valves. All told we may have collected 5,000 shells in these four dredges, suggesting that the sea floor in this area is covered in these shells. Live material was less abundant (there may be a number of reasons for our not collecting live animals as efficiently as we might have, including the effectiveness of the dredge, or the possibility that at this time of the year many animals may burrow further into the sediment), but we did retrieve thirty or so live animals, and also a large number of articulated pairs, which can generally be assumed to be very recently dead*.

*This is important for chronology construction. Shells from live collected animals with a known date of death can be used to anchor the chronology, while the articulated shells can be assumed from their condition to have died very recently and should easily crossmatch with the live specimens.

Ben Allinson, Sarah Holmes and Stella Alexandroff in the coffee room at School of Ocean Sciences, Bangor with a 130mm Arctica islandica shell.

The other day we received delivery at Bangor of the biggest Arctica islandica shell any of us had ever seen. To put this in context, up until now I’d thought they couldn’t get bigger than about 122mm at the widest point. This one came out at a cool 130mm. It was found on a beach on the Hebridean island of Lewis by Roy Bentham, a retired truck driver who takes a keen interest in our work.

Stella will be working on its sclerochronology, so as and when we measure the growth increments we’ll let you know how long it lived and whether we can fit it into a chronology.

There’s an excellent series in Discover magazine on climate work with Arctica off northern Norway. ARAMACC ESR Irene Ballesta is out there right now, with Rob Witbaard, Al Wanamaker, Michael Carroll and other researchers from Bates College in the US.

The lady speaking in Norwegian at the end of the piece is a program manager at the Norwegian Research Council. She’s saying how important it is to understand past climate history to determine what the effects of future changes will be, and that this research will provide an important piece of the overall puzzle.

10 Early Stage Researchers (ESRs) have now been appointred or are about to be appointed at six centres across Europe. Each ESR position is attached to a host university for the award of a PhD.

The ESRs will be trained in the full range of skills associated with shell-ring research (sclerochronology), including climate reconstruction, climate modelling, biological and environmental drivers of shell growth, and novel geochemical proxies.

From the point of view of the relatively new science of sclerochronology, ARAMACC presents a great opportunity to move the field forward with an injection of new blood and new ideas.

The ESRs will working on projects based around four broad application groups (Work Packages 1-4):